Navajo Mining Company Purchased a Mine in 2013 for $3

Navajo Mining Company purchased a mine in 2013 for $3 400 000. It was estimated that the mine contained 200 000 tons of ore and that the mine would be worthless after all of the ore was extracted. The company extracted 25 000 tons of ore in 2013 and 30 000 tons of ore in 2014. What is depletion expense for 2014?

A) $425 000
B) $680 000
C) $510 000
D) $340 000